1. Technical Field
The preset disclosure relates to a digital system with output from different modes, and more particularly to a combined digital output system combined with a common mode circuit and a differential mode circuit, and providing a common mode signal, a differential mode signal or an output signal with combination of the two.
2. Related Art
Referring to FIG. 1, a double differential mode recording system is an ordinary known technology for recording electromyogram signals or electroneurogram signals, and reducing common mode interferences. Two first-rank amplifiers 11 and a summing amplifier 12 are required in the system, in which, the first-level amplifier is connected to an electromyogram sensor 13, and a plurality of sensing units 14 is located in the electromyogram sensor 13 to sense different electromyogram signals. The first-rank amplifier 11 may obtain the electromyogram signals provided by the electromyogram sensor 13, and the electromyogram signals include the electromyogram signals and interference signals. When the electromyogram signals are recorded in a double differential mode recording manner, the system lays particular emphasis on the analysis of the electromyogram signals generated by muscles near the electromyogram sensor, and excludes high-gain signal data generated by the electromyogram signals in the common mode, and afterwards, digitalizes the measured analog electromyogram signals through an analog/digital (A/D) converter 15, so as to provide reference for the observers.